SOI Design: Analog, Memory and Digital Techniques

407 Pages·2003·24.53 MB·English

by  Andrew Marshall

SOI DESIGN
ANALOG, MEMORY
AND
DIGITAL TECHNIQUES
SOI DESIGN
ANALOG, MEMORY
AND
DIGITAL TECHNIQUES
by
Andrew Marshall
&
Sreedhar Natarajan
Texas Instruments Incorporated
KLUWER ACADEMIC PUBLISHERS
NEW YORK,BOSTON, DORDRECHT, LONDON, MOSCOW
eBookISBN: 0-306-48161-8
Print ISBN: 0-7923-7640-4
©2003 Kluwer Academic Publishers
NewYork, Boston, Dordrecht, London, Moscow
Print ©2002 Kluwer Academic Publishers
Dordrecht
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SOI Design: Analog, Memory & Digital Techniques
To Judith, Amy and Elise for their enduring patience and encouragement.
-- Andrew Marshall
To my wife Chandra for her patience and support, my Parents, my brother
Sriram and his family, my wife’s family, and friends for their continued
encouragement.
-- Sreedhar Natarajan
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SOI Design: Analog, Memory & Digital Techniques
Table of Contents
Preface xix
Acknowledgements xxi
Chapter 1: Overview 1
1.1 Silicon on Insulator – a brief Introduction 1
1.2 Circuits and SOI 2
1.3Technology and SOI 3
Chapter 2: SOI Materials 5
2.1 Silicon on Heteroepitaxial Substrate 5
2.2 Silicon-Oxide-Silicon SOI substrates 6
2.2.1 Separation by Implantation of Oxygen 6
2.2.2 Wafer-Bonding methods for preparing SOI 8
2.2.3 SOI Materials Summary 11
2.3Comparison of SOI and Bulk 11
2.3.1 Isolation Techniques 11
2.4 SOI Technology Advantages 16
2.4.1 Capacitance Reduction 16
2.4.2 Reduced Short Channel Effect 16
2.4.3 Lower Device Threshold 16
2.4.4 Soft Error Rate (SER) Effects 17
2.5 Performance 17
2.6 Partially and Fully Depleted-SOI 18
2.7 Technology Scaling 21
2.8 SOI Device Properties 22
2.8.1 Source/Drain-to-Substrate Capacitance 22
2.8.2 Gate Leakage 22
2.9Body Effects 23
2.9.1 Bipolar Effect 23
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SOI Design: Analog, Memory & Digital Techniques
2.9.2 Kink Effect 24
2.9.3 Capacitive Body Effects 26
2.10 Body Ties 29
2.10.1 Body Tied to Substrate 31
2.10.2 Body-tied to gate Configurations 32
2.10.3 Resistive Body Tie 33
2.11 Device Noise 34
2.12 Self Heating 36
2.12.1Self Heating from elsewhere on the same chip 38
2.12.2Self Heating from within a sub-circuit 39
Chapter 3: Components 47
3.1 MOS devices 47
3.2 Diodes 49
3.3 Bipolar Transistors 49
3.4 Lateral DMOS 51
3.5 Drain Extended Devices 53
3.5.1 Design of an SOI high voltage DEMOS device. 55
3.6 Compound High Voltage SOI Structures 56
3.7 Passive Components 57
3.7.1 Resistors 57
3.7.2 Capacitors 58
3.7.3 Inductors 59
Chapter 4: SOI Modeling 63
4.1 Modeling Introduction 63
4.2 Example SOI spice deck 66
4.3 Models 68
4.3.1 BSIM 68
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SOI Design: Analog, Memory & Digital Techniques
4.4 Alternative Model Options 70
Chapter 5: Layout for SOI 75
5.1 Introduction to Layout for SOI components 75
5.2 Converting designs from Bulk to SOI 77
5.2.1 Diodes 77
5.2.2 Bipolar Transistors 79
5.3 Layout for Minimization of Thermal Self Heating Effects 80
5.3.1 Cross coupling with thermal coupling 81
5.4 Output Stages 83
Chapter 6: Static SOI Design
6.1 Introduction 85
6.1.1 Lower Fan Out Capacitance 87
6.2 Decreased Body Effect 87
6.3 Gate Leakage 88
6.4 Static Inverter Characteristics 89
6.5 Body Voltages in SOI Inverters 92
6.6 Body Voltage Convergence 94
6.6.1 Delay vs. effective gatelength 94
6.7 Noise Margin In Inverters 95
6.8 Nand Gate Response 96
6.8.1 Body Voltage Response in Nand Gates 101
6.9 Nor Gate response 103
6.10 Static OR-AND SOICMOS Circuit 104
6.11 XOR Gate response in SOI 107
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SOI Design: Analog, Memory & Digital Techniques
6.12 Ring Oscillator Performance 108
6.12.1 Nand Fan-out of 3 ring-Performance vs. 109
6.12.2Nand fanout of three - Performance vs supply 110
6.12.3 Nand fan-out of one 110
6.13 Pass Gate Response 112
6.13.1 Pass transistor basedcircuits 114
6.13.2Pass transistors based Multiplexers 115
6.14History Dependence 117
6.15 SOI vs BULK : Performance benefits in Digital Circuits 118
6.16Floating body and hysteresis effect 119
6.17 Non Ideal diode characteristics 120
Chapter 7: Dynamic SOI Design
7.1 Introduction 125
7.2Dynamic Circuit Response 125
7.2.1 Dynamic History Effect 125
7.2.2Dynamic Charge Sharing 126
7.2.3 Capacitive Coupling Effects 126
7.2.4 Keeper Devices or Bleeders 127
7.3Dynamic Circuit Design Considerations 129
7.4Re-ordering and Remapping 130
7.5Logical Remapping 130
7.6Complex Domino 132
7.6.1 Three-input Domino OR Gate 132
7.6.2 Dynamic AND-OR Domino Gate 133
7.7No-Race Logic (NORA) 136
7.8 Dynamic Noise Suppression 141
7.9Design Issues in Dynamic 2-way NAND Logic 142
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SOI Design: Analog, Memory & Digital Techniques
7.10 Dynamic 2-Way OR Circuit 145
7.11Dynamic Cascade Switch Logic 147
7.12 Clocked CMOS 149
7.13 Pulse Stretching in Dynamic Circuits 153
7.14Dynamic Wide-OR 157
7.15 Non Overlapping Clocks 158
7.16 Pass transistor based Non-Overlapping Clocks 159
7.17Low Power SOI Techniques 161
7.17.1 Dynamic Threshold SOI CMOS 161
7.17.2 Dynamic ThresholdMultithreshold CMOS Logic 162
7.17.3 Dynamic Threshold Pass Transistor Logic 164
7.17.4 Dynamic threshold voltage Full Adder 165
7.17.5 Dynamically Body Bias SOI CMOS Inverter 174
Chapter 8: SOI SRAMs
8.1Introduction 181
8.2 SRAMCellstructures 182
8.3 Design considerations and specifications for SRAM Cells 185
8.3.1 4T-2R Polysilicon resistor load SRAM 186
8.3.2 SRAM cell with 2 thin-film transistor loads 186
8.3.3 6T-PMOS Load SRAM cells 186
8.4 Four Transistor SRAM using Self-body biased MOSFET 187
8.5 Basic SOI SRAM Cell operation 189
8.5.1 READ Operation in a SRAM Cell 189
8.5.2 Write operation in SRAM Cell 193
8.6Cell Stability 197
8.7 SRAM Junction & Bit line capacitance 201
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SOI Design: Analog, Memory & Digital Techniques
8.8Decoders 201
8.9 SRAM Architecture 203
8.10Bit Line Related Architecture 205
8.11 SenseAmplifiers 206
8.11.1 Differential Amplifier 207
8.11.2 Clocked Dual Slope Sense Amplifiers 211
8.11.3 Dynamic Body Charge Controlled Sense Amplifier 213
8.11.4 SenseAmplifier Techniques 218
8.12 Mismatches in Sense Amplifiers 220
8.12.1 Offset Considerations for High Speed Sensing 223
8.13 Mismatch in SRAM Cells 225
8.13.1Body Bias 225
8.13.2 Supply Rail Droop 225
8.13.3Body-to-Body Coupling 226
8.13.4 Common Mode Supply Rail 226
8.13.5 MOS Junction capacitance 226
8.13.6 Self Heating 226
8.14 SER Issues in SRAMs 227
8.15 SOI CMOS Memory Challenges 228
8.16Destructive read-out characteristics of SRAM 229
Chapter 9: SOI DRAMs
9.1Introduction 235
9.2DRAM structure and Operation 237
9.3Memory Array 238
9.4DRAM cell storage 241
9.4.1 Storage to Bit Line Capacitance 243
9.5 SOI DRAM Process 244
9.5.1 Smart-cut for DRAM 246
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